The prob I used to have washing engine bays (back when I was 16) is water in the distrib cap, pull off the cap, wipe it out good, spray it with WD-40 (Water Displacer #40, actual meaning) and put it back on.
Good place to start, it didn't ever just dry itself out either. Now I keep water away from the electronics in the bay, and start it up right after to help dry it.
Edit to add: it caused the same prob you are having.
"DRIVE IT LIKE A FIERO"
engine to be determined
'87 Duke (Sold)'87 Quad 4 H.O. '87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!!
^^^^ Now in the Construction Zone^^^^Las Vegas Fiero Club
Parts/Sales/Service/ClubFiero Road Club Of Northern Nevada
[This message has been edited by sardonyx247 (edited 10-14-2014).]